What ideas did the early Vietnamese literary works mainly describe and convey?

Biography of Guo Yunxian, a long poem, is an early work, which describes the unfortunate experience and tortuous marriage of poor scholars Guo Yunxian and Qiao Yuee, exposes social evils, criticizes the moral decay of feudal society, and has an anti-feudal tendency. However, the works also reflect that the writer still has the feudal consciousness of the three cardinal guides and five permanent members of Confucianism. Ruan Tingying's best works are more than 50 poems, several eulogies and poems. Being brave is not only a tribute to the heroes who died on the battlefield, but also a condemnation of traitors. In many other poems, Ruan Tingying praised the rebel soldiers who resisted the enemy tenaciously and portrayed the image of simple, hardworking, brave and simple rebel.